This is the unedited first paragraph of an infectious disease specialist's response to an email inquiry from our clinic regarding screening for schistosomiasis, a parasitic tropical disease that typically presents with abdominal pain and diarrhea:
I'll bet you've never seen an emoticon used in that context.
Every infectious disease physician and microbiologist I've encountered is that enthusiastic. At the ID conference I attended last fall, every presenter spoke with actual affection for his favourite microbe, announcing that he could talk about the subject all day long and sighing when his time was up.
Exhibit B would be their penchant for bow ties.